Frank m



(No Model.)

I'. M. LEAVITT.

vSTEAM PUMP.

No. 323,346. n Patented Ju1y28, 1885.

No n m ll l ill I I I IUI Il.f "la u TERS. Phaimlhogrnghef. Washington.C!4 C.

lJNrrnn Sintes Parleur @teren FRANK M. Lnnvirr, or new venir, itssicsonro w. nniss, or BROOKLYN, N. Y.

STEAM-PUMP.

SPECIFICATION forming part of Letters Patent No. 323,346, dated July 28,1885.

Application filed August 16, 1894. (No model.)

sageways leading from each end ofthe valvcv plunger cylinders into theend of the main cylinders, such passage-way heilig controlled by avalve, as hereinafter more fully described and claimed.

.Figure l represents a plan view of a direct acting duplex steampump,the steam cylinder and chest being shown in horizontal section. Fig. 2represents a cross-section of the steam chest valve and plunger, takenat the line X X, Fig. l.

Having described my invention by reference to the igures illustrated inthe accompanying drawings, l will now proceed to describe it byreference to the letters marked thereon, in which- A represents asteam-cylinder; A', a corresponding` steamcylinder. In these cylinderspistons B and B', respectively, move reeiprocally. Steam is alternatelyadmitted to and exhausted from each end ot' the cylinder A through portsc and b, (shown in dotted lines,) hy means of slide valveGin theordinary manner. Steam is alternately admitted to and exhausted fromcylinder A' through ports a and D', (shownin dotted lines,) hy means ofslide-valve C'.

D and D represent projecting lugs on the outer surface of each of thevalves (l and C'. These lugs engage, respectively, in a groove insteam-actuated plungers Il and E' in such a manner as to make valves Gand C' to move in unison with them.

d and e and d' and e' represent recesses in the faces ot' valves C andC'. y

F and I1" represent steainchests, in which the valves C and C'respectively operate, the said chests heilig provided with suitablecylinders, S and S', in which the plungers E and E' move.

Z' represents a port or passage-way for steam-one end connecting withthe righthand end of the plunger-cylinder S and the opposite end withthe steainchest F', in such a position that this end of the port isalways open into recess e at whichever end of its stroke the valve U'may be.

k and m' represent steam-ports or passageandthe other ends en tering thesteam-chest F', in such a position that when the valve C is at theextreme left ot' its throw, the port lt' is in communication with portZ' through recess e', and the port m' is closed hy the valve C, andconversely, when the said valve is at the extreme right ot its throw,the port m' coniniunicates with port i' through recess c', and port lr'is closed hy valve C. The port lr enters cylinder A' at a point distantfrom the letthand en d oi'said cylinder somewhat greater than thethickness ot' the piston B', and the port m' enters at or near theright-hand end of the cylinder A.

It will he seen that the three ports k' l' and m", together with recessc', form a system ot' steam-ports to control the steam in the righthandend of cylinder S. The left-hand end of cylinder S is controlled in asimilar manner by the three ports f g' and h', together with recess d',and likewise the two ends of cylinder S are controlled hy the system ofports j', g, and h and recess d, and the system 7.1, l, and m and recessc, respectively. Gare must he taken thatvthe portsf and j", m and menter -the cylinders A and A at their respective ends beyond the tra-velofthe pistonvalves B and B', so that these ports are never covered orstopped by said pistons. These ports may communicate with main cylindersby being connected with the main ports a l) a.' b', re spectively,though by prefere-nce are connected directly with said cylinders, ashereinabove described.

Operation Then the pistons and valves are in the position shown in' Fig.1, port b' is uncovered by valve C'. ln consequence, live steam isadmitted from steamfspace in chest F' into the right-hand endet1 thecylinder A', holding the piston B against the left-hand end of itsstroke, as shown, the lett-hand end ot' the said cylinder beingconnected with the ways, oneend of each entering cylinder A IOO mainexhaust P' through port a' and recess O in valve C'. Ports m' and h' areclosed by valve C', as shown. Live steam passes from cylinder A' throughport 7c', recess c' in valve C', and passage l', into the right-hand endof the valve or plunger cylinder S, operating against plunger E, holdingsaid plunger, and with it valve C, at the left-hand end of their throw,the left-hand end of cylinder S, having connection with the mainexhaust-port P' through passage g', recess d', passage f', lefthand endof the cylinder A', main port a', and recess O', main port b is thusuncovered, allowing live steam to pass from chest F through said portinto the right-hand end of the cylinder A, moving piston B in thedirection of the arrow from right to left, the opposite end of the saidcylinder being connected with the main exhaust P through port a andrecess O in valve G. While piston B is making this stroke, the ports hand m are closed by the valve C, and the right-hand end of cylinder S'is connected with main exhaust P through port g, recess d, and port f,left-hand end of vthe cylinder A, port a, and recess O in valve C, andthe left hand end of said cylinder S' is connected with the sameexhaust-port P through port Z, recess e, port 7c, left-hand end ofcylinder A, port a, and recess O. The pressure against each end of theplunger E' is thereby7 balanced, and the plunger remains stationary,whatever back pressure there may be in the left-hand end of the cylinderA. When piston B reaches the lefthand end of its stroke, it passes port7c, bringing the same into communication with live steam in theright-hand end of the cylinder A. Steam passes through ports k, recess ein valve C, port l, into the left-hand end of the cylinder S', causingplunger E', and With it valve C', to move to the opposite or right-handend of its stroke, the right-hand end of cylinder S' being still incommunication with the main exhaust-port P, as before described. Portci' is by this movement of the valve C' brought in communication withlive steam in chest F', and port b' with main exhaust-port P', forcingpiston B' toward the right-hand end of its stroke. At the end of eachstroke of the pistons B and B', a similar cycle ot' operations is gonethrough, producing a continuous alternate action of the pistons.

The purpose of exhausting the steam from the plunger-cylinders S and S'into the ends of the cylinders A and A', and thence through the mainports into the main exhaust-ports P and P', instead of directly into thesaid main exhaust-ports is, that when either piston reaches the end'ofits stroke-as, for example, when piston B reaches the left-hand end ofthe cylinder A and steam is admitted through port 7c into the left-handend of the valve-cylinder, as described, causing the plunger E',

and with it the valve C', to pass to the righthand end of theirstroke-the right-hand end of cylinder A' is placed in communication withthe left-h and end of the valvecylinderS through port h', recess d', andport g', and if the opposite or right-hand end of cylinder S were at thesame time connected direct with the main exhaust, whatever steam did notpass out of the right-hand end of the cylinder A' through the main portb' would operate against the left-hand end of plunger E, tending tothrowl this plunger before the proper time, and cause irregular strokesof main piston. Whether the irregular action occurs or not will dependon whether there is sufiicient back pressure in the main cylinder toovercome the friction on the main valve. By leading the exhaust-passagesinto the end ot' the cylinders A and A', or into the exhaust-ports a and11,60' and b', respectively, in close proximity to the end of the maincylinders, the valve-plungers will receive the same pressure on bothends when the main pistons, governing their action, are at any part oftheir stroke, except between-the two ports at the same end of thecylinder. In consequence of this arrangement it is impossible for eithervalve to throw, no matter how much the back pressure in the maincylinders may be, until the piston governing its action has reached theeXtreme end of its stroke.

It is obvious that a similar arrangement ot' 95 ports may be applied tothe piston or balancevalve instead of the slide or flat valve shown, andit is equally obvious that the sa-me system of exhaust-ports andvalve-motion can be applied to a single or duplex pump, or to 10o a pumpwith any increased number of cylinders.

lVhat I claim as new, and desire to secure by Letters Patent, is-

l. In a direct-acting duplex steam-pump,

having its valves operated by direct steampressure, exhaust-ports orpassage- Ways leading from each end of the valve-plunger cylinders intothe ends of the main cylinders, as described, each passage-waycontrolled by a 1ro valve arranged substantially as described, as andfor the purposes stated.

2. In a direct-acting duplex steam-pump, having its valves operated bydirect steampressure, exhaust-ports or passage-ways lead- 1 1 5 ing fromthe ends of the valve-plunger cylinders into ports leading from the endsof the main cylinders into the recess O and O' in main valves, eachpassage-way controlled by a valve combined and arranged as described, as12o and for thepurposes stated.

FRANK M. LEAVITT.

'itncsses 'EDWIN H. RIsLnY, XVM. G. WELLS.

